IN THE MEDITERRANEAN. 
243 
in the morning, I watched carefully for the appearance of flame, but could not 
detect it; the lightning traversed in various directions the volcanic atmosphere, 
but it was never accompanied by any appearance of the explosion of inflam¬ 
mable gases. 
The results of the preceding observations are all of a negative kind. Still 
hoping to ascertain something positive relative to the cause of the phenomena, 
after my return I availed myself of every opportunity of examining the pro¬ 
ductions of the volcano, and through the kindness of several friends I have 
been liberally supplied with materials. 
The solid products, or matters ejected, which I have examined, have appeared 
to differ more in form than in chemical composition. They have occurred in 
the form of fine sand or ashes, of very porous light cinders, of comparatively 
heavy and compact cinders, and of fragments of vesicular lava; of the last 
variety of product, I have seen only two small specimens, which were taken 
from the crater on the 2nd of August, by Captain Senhouse, R.N., who was the 
first who succeeded in landing on it, and who has proposed for it the name of 
“ Graham Island.” Both these masses were of a dark gray colour, contained 
augite, and very much resembled vesicular basalt, or the common lava of Etna 
and Vesuvius, such as is quarried at Portici and at Catania. The specific 
gravity of one of them was 2*07 ; that of the other, which was more compact, 
2 * 70 . The very light, spongy cinder, which abounded floating on the sea, 
varied in colour between black and gray. Reduced to fine powder by tri¬ 
turation, and the greater part of the entangled air got rid of, it sunk in 
water, and was found to be of the specific gravity 2*64. The fine sand or 
ashes, which fell in our boat when we were in a shower of it, was of the specific 
gravity 2*66, and some which fell on us in the eruption, close to the volcano, 
2*75. The cinders, of which the crater appears principally to consist, are 
commonly of a dark colour, and almost black, and they are generally very 
porous or spongy. Occasionally they are coloured superficially by yellow 
ochre, or a crust of clay mixed with a little peroxide of iron. One specimen, 
reduced to powder, was of the specific gravity 2*74. 
Every specimen of solid matter that I have examined has contained saline 
matter similar to that of the sea, and a slight trace of sulphur. In every spe¬ 
cimen tried, reduced to fine powder, there were particles which were attracted 
